Dear all, I am engaged in studying gene expression in forebrain. What I would like to know is if there are specific group of genes like that of RBPs, TFs, cell adhesion molecules, neurotransmitters etc specifically expressed in this region. Therefore I am assimilating data from different parts of the forebrain and studying differential gene expression. Since I am gathering data mostly from sequencing and profiling studies (already published), I need to understand exactly how many samples should I study? Can I compare data sets from two different studies? Since I will be studying and comparing the control (Wt) samples, most data generated from similar platfrom like either Illumina RNA-Seq or Microarray should have similar pattern. I have a fear that if I randomly take two RNA-Seq studies (generated on Illumina platform), there will be a disparity in gene expression. Also, if I study only one data set, the outcome might be biased and not true. How do you think I should approach this problem?